This invention relates to synthetic resin articles having a porous structure of the general type previously referred to in the art as macroporous, macroreticular, or as having microscopic channels. Such articles hereinafter referred to as macroporous articles have been found to possess certain advantages when compared to prior art gel or "microporous" resins. The most prominent of these advantages is increased mechanical strength while maintaining permeability to fluids. This in turn facilitates the flow and diffusion of liquid phases through the resin article and enhances the usefulness of such articles for processes such as ion exchange, absorption, adsorption, catalysis, etc.
More specifically, the invention relates to crosslinked porous polymers wherein porosity is introduced by a polar preferably hydrolyzable linear polymer additive in the monomer mixture which may be later removed from the porous crosslinked body.
The prior art teaches various methods of making crosslinked macroporous resins. The process is generally carried out by the following steps (a) polymerization of styrene/divinyl benzene in the presence of linear apolar preformed polymer (b) removal of preformed linear polymer (c) conversion of crosslinked polymer to cation or anion resin. Such processes are described in U.S. Pat. No. 3,122,514 (Abrams), Hungarian Pat. No. 142,661 and British patent specification No. 1,082,635. It has been found in the prior art that the removal of preformed linear polymer from the linear polymer and resin matrix mixture is hindered due to the apolar character of both the linear polymer and resin mixture which forms a continuous phase of chemically similar matter. If the extraction of linear polymer is not done efficiently, the linear apolar polymer such as polystyrene forms a slime and impurity during the chemical transformation of the polymer thus affecting the quality of ion exchange resin made out of it. Another deficiency of the systems of the prior art is that due to smooth and continuous compatibility between the insert and matrix no real interfaces are formed by the two materials thus causing poor porosity in the resin after the extraction of the insert. The drawbacks of the prior art are overcome in the present invention by providing a high porosity and larger pore diameter resin.